Printing telegraph receiver



June 14, W38. M. AMANN ET AL 5,

PRINTING TELEGRAPH RECEIVER Filed Feb. 29, 1956 a Sheets-Sheetl June 14, 1938. M. AMANN ET Al.

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June 14, 1938.,

M. AMANN ET AL PRINTING TELEGRAPH RECEIVER Filed Feb. 29, 1936 6 Sheets-Sheet 3 fm/emors MAX AMA/VA! June '14, 1938 M. AMANN ET AL 2,120,850

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Patented June 14, 1938 UNITED STATES PATENT OFFICE PRINTING TELEGRAPH RECEIVER Max Amann, Alfred Lahl, and Hans Hatzinger, Frankfort-on-the-Main, Germany 17 Claims.

This invention relates to printing telegraph receivers having a type wheel and a selecting mechanism which comprises a set of rotary permutation or code discs and a set of testing members adapted to cooperate with the discs and which can be set into different positions by means of a single magnet. In this type of receiver, the various testing members are successively set by the magnet under the influence of the successive current impulses of a received telegraph signal through the agency of a rotating device. The whole set of testing members is then moved towards the rotating discs which have grooves in their peripheries arranged so that the testing members can only engage in them and thus lock the discs in one particular angular position of the discs for any one setting of the testing members. The type wheel is connected to the code discs and rotates with them. When the discs are at rest, a particular type lies in front of a printing hammer by means of which this type can be printed.

The object of the invention is to reduce as far as possible the load borne by the above-mentioned magnet when setting the testing members and to transmit the force to be used for setting these testing members through an auxiliary device so that the sensitivity of the magnet can be increased and the magnet can be made to respond to weak current impulses. In accordance with the invention the setting of the testing members is effected as a consequence of the position taken up by a rotary device controlled by the magnet and as a result of the force maintaining this device in rotation. The rotary device is positively set during the rotation so as to determine a particular setting of the testing members and is held in the set position merely by bringing the armature of the magnet into one of its two extreme positions at particular intervals of time. The testing members are thus set only indirectly in dependence upon the position of the armature. The magnet itself thus does not exert the force for setting the rotary device and for setting the testing members. The position of the magnet armature is moreover positively determined by the rotary device and the setting of the testing members is effected positively according to the position assumed by the rotary device which is itself dependent upon the position of the armature, by the force maintaining the device in rotation.

In order that the invention may be thoroughly understood and be more readily carried into effect, an example of construction in accordance therewith will now be described with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a telegraph receiver in accordance with the invention.

Figure 2 is a sectional elevation of the re- 5 ceiver.

Figure 3 is a cross-section taken on the line IIIIII in Figure 1.

Figures 4-6 illustrate details of the mechanism shown in Figure 3.

Figure 7 is a cross-section taken on the line VIIVII in Figure 1.

Figure 8 is a diagrammatic representation of the selecting mechanism.

Figures 9 and 10 show the selecting mechanism in two testing positions.

Figure 11 is a perspective View of the testing levers of the selecting mechanism.

Figure 12 shows diagrammatically the positions taken up by various parts of the selecting mechanism on selection of the letter A.

Figure 13 is a cross-section taken on the line XIII--XIII in Figure 1.

Figure 14 is a sectional plan View of part of the arrangement shown in Figure 2.

Figures 15 and 1'7 are plan views showing in two different working positions the devce provided for bringing the printing mechanism into operation.

Figures 16 and 18 are respectively a side elevation and a front elevation of part of the device shown in Figures 15 and 17, and

Figure 19 is a sectional elevation to a larger scale of a detail illustrated in Figures 15 and 17.

The illustrated receiver has a single receiving magnet and the whole of the members which are necessary for printing a type are mechanically controlled during and after reception of the appropriate code signal.

The type is carried by a type Wheel and the 40 printing takes place on a paper strip when the type wheel is at rest. The type wheel can assume 64 different positions and one of 32 different positions can be selected on reception of a 5-unit code signal. Shift signals cause the type wheel 45 to be stepped backwards or forwards through l/64th part of a revolution. In this way, figures and signs can be printed in addition to letters of the alphabet. In some positions, corresponding to switching steps and the like, printing is 50 prevented.

The setting of the type wheel is controlled by 'means of a selecting mechanism comprising two sets A and B each of 5 testing levers each of which cooperates with a pair of code discs. The testing 55 levers can be displaced individually relatively to the pai of code discs associated with them. This displacement is effected by means of a distributor which is rotated as synchronously as possible with the transmitting distributor or the received signals. The various testing levers are displaced successively and the displacement is controlled indirectly by the receiving magnet in accordance with the received code signal. When the testing levers have been set in their displaced positions, they are brought, as a set, into contact with the pair of code discs associated with them, so that they can engage, as a set, in the grooves formed in these discs when the latter are subsequently rotated. This engagement of the testing levers in the grooves in the code discs is only possible in one of 32 positions of the code discs, this position being determined by the setting of the testing levers. The type wheel rotates with the code discs and thus takes up the position de termined by the selecting mechanism and in which the code discs and the type wheel are stopped by the testing levers when thelatter come into the grooves in the code discs. The printing or other operation then takes place with the type wheel at rest. The selection of the position of the type wheel corresponding to the setting of one set of testing levers can take place While the other set of testing levers is being set by a subsequent signal.

The printing of the selected type (or the shift or other step) is effected directly by the printing mechanism after the code discs and the type wheel have been brought to rest. These steps are effected by a motor.

The receiver (Figure 1) is driven by a. motor I32 through a worm and a worm wheel I84, I85. This single motor is also used to drive and control the distributor arm I52 (and the parts connected therewith), to rotate the code discs I93 I98 and the hub I25 which carries the type wheel I25 and to control the parts connected with the printing or with the prevention of printing.

The worm N14 is connected to the shaft I81 of the receiver through a flexible coupling I68. The shaft I81 carries two toothed wheels H2, H3. The wheel II2 meshes with a wheel II4 of twice its own diameter and forming part of the startstop mechanism. The wheel II3 meshes with a smaller wheel H5 which drives the selecting mechanism. i8 of the receiver by means of a hub I I6 forming one part of a dog clutch (Fig. 2) and a grub screw H1.

The wheel H3 (Fig. 2) is mounted to rotate on the type wheel shaft I22 which is coaxial with the shaft H8. The type wheel I25 and the cam discs I21 associated with it are mounted on. the carrier member I26 keyed to the front end of the shaft I22.

At its front end, the shaft I81 has fixed to it one part 262 of a dog clutch (Figures 15 and 17) by means of which the parts which come into play for eifecting printing are coupled.

, Two sleeves E28 and I29 (Figs. 2 and 14) are freely mounted on the continuously rotating shaft H8 of the receiver. The sleeve I28 has forked lugs 592 (Fig. 2) projecting from it in which engage dogs I9I on the part I38 of the clutch i363, H6, which part is free to slide on the sleeve I28. A helical spring E32 abuts against the lugs I92 and the part I38 and is housed within a drum I3I rigidly fixed to the part I38. This spring I32 tends to cause the clutch I38, II6 to engage but is prevented from so doing in the The wheel H4 is fixed to the shaft normal position illustrated in Fig. 2 by the pawl I33, seen in Figs. 3 and 4.

The sleeve I28 has oblique grooves I34 (Fig. 14) cut in it at one of its ends in which engage dogs or lugs I35 projecting radially inwards from a ring I39, fixed to a sleeve I31. This sleeve I31 is capable of axial displacement and is guided during such displacement by guide slots I38 in the sleeve H29. A drum I53 to whichv is fixed the distributor arm I52 is mounted on the sleeve I29. This drum can be reciprocated easily along the sleeve I29 without angular displacements and, for this purpose is provided with pins I54 (Fig. 2) ending in rollers which lie in the grooves I33 formed in the sleeve I29.

The sleeve I29 terminates at its forward end in a flange I59 to which are fixed a cam disc I68 and a wheel I32.

Rotation of the sleeves I28 and I29 with the shaft II8 which always takes place to the extent of half a revolution is effected by the pawl I 33, (Figs. 3 and 4).

The pawl I33 is pivotally mounted at I13 and its curved end normally projects into one of two diametrically opposite openings I'II in the drum i3I and holds the drum in the stop position. In this position, an oblique surface I 88 bounding the opening III bears against an oblique surface at the upper left hand end of the pawl I33 so that the clutch I18, I38 (Fig. 2) is held disengaged.

The drum I3I is prevented from rotating backwards by the check pawl I11 (Figs. 3 and 5) pivotecl at H8 and which normally abuts against the upper edge of the opening I1I opposite to that in which the pawl I33 is engaged.

A spring I13 urges the pawl I11 into engagement and tends to hold the pawl I33 out of engagement with the openings I'II in the drum I3I.

In the normal position, the spring I16 is prevented from swinging the pawl I33 clockwise because the lower end of the arm I15 attached to the pawl abuts against the cranked end of a bar I85 forming part of a pivotable member I83, (Fig. 6).

A third arm !14 (Fig. 3) moving with the pawl I33 is disposed in the plane of two diametrically opposite abutments I19 formed on the edge of the drum I3I. The arm I14 can only come into contact with the abutments I19 when the pawl I33 is pivoted out of the normal position. This only happens shortly before the completion of the half revolution of the drum I3I. The bar I85 can be pivoted about the pivot I831 against the action of a weak spring I84. The arm I82 of the pivoted lever I83 lies opposite the end I3! of the armature I48 of the magnet I58 (Figs. 3, 6 and 7) When the armature I48 drops, its end I8I abuts against the arm I82, pivots the lever I33 against the action of a spring I84 and releases the arm I15. The pawl I33 is now effectively acted on by the strong spring I16 and, as a result, the arm I15 rides over the sloping face. I86 (Fig. 6) of the cranked part of the bar I 85. The force thus exerted on the arm I85 assists in the pivoting of the lever I83 and the pawl I33 is thus elfectively un-latched by a small movement of the armature I48.

In the normal position, the magnet coils are supplied with current and hold the armature I48 in the position illustrated in Fig. 7 against the action of the spring I81.

The disengagement of the pawl I 33 from the opening I1I in the drum I 3| when the armature I48 drops allows the compression spring I 32, (Fig. 2) to bring the teeth on the clutch member I39 into engagement with the teeth on the rotating clutch member IIB. From this instant onwards, the shaft I I8 is coupled by the dogs I9I to the sleeves I28 and I29 and the whole of the parts guided by the sleeves, including the distributor arm I52, are rotated together.

Shortly before the drum I3I has completed half a revolution, one of the abutments I'I'9 (Fig. 3) abuts against the. arm I'M and turns the pawl I33 against the action of the spring I75. At this instant, the opening III in which the pawl Ill was previously engaged is opposite the pawl I33. The sloping surface I88 bounding this opening now abuts against the head of the pawl I33 and the drum I3I is moved in the direction of the arrow shown in Figure 4. This causes the clutch I39, IIB to be disengaged, the drum I3I to be stopped and the arrangement to be brought to rest after exactly half a revolution.

The selecting mechanism comprises two sets A and B of testing levers I58 and the code discs I93-I.96. (Figs. 8-12). The testing levers I58 are not shown in Fig. 2.

Each testing lever I58 is mounted on a pin or shaft I98 (Fig. 11). The latter are. mounted so as to be movable axially in the brackets IZI and the side plates 25L (Figs. 1 and 11). The side plate 29I for each set of levers is held at the correct distance from the bracket I2I by a distance piece 292. The pins or shafts I98 and therefore the testing levers on them, can be set into a forward or a backward position by means of control levers I51 (Figs. 1 and 13) which project through slots in the flat ends I99 of the shafts I98. They are maintained in these positions by springs 299 (Fig. 11).

The testing levers I58 can be displaced parallel to the axis of the code discs, the levers I58I--V of the set A relatively to the code discs I93, I94 and the levers I53I'-V' of the set B relatively to the discs I95, I95 This is diagrammatically illustrated in Figure 8. The distance apart of the code discs in a pair is less than the sum of the thicknesses of two testing levers I58, (Fig. 11). The tails 295 of the. testing levers of each set abut against each other and are connected together by a spring 297 or 291. The displacement of the testing levers parallel to the axis of the code discs does not bring their tails 294 out of contact with each other. This is clear from Figure 11, where the testing lever I58III is shown in the extreme right hand position and the testing lever I58IV in the extreme left hand position.

This mutual support of the testing levers I58 prevents independent movement of the levers about their shafts I93.

The topmost lever of the set B and the lowermost testing lever of the set A each has a rear ward extension 295 and the topmost lever of the set A and the lowermost lever of the set B a similar extension 295' (Figs. 9 and 10). A spring 206 is anchored at one end to the projection 395 of the lever I58V and at the other to a control lever I61; a spring 255 is similarly connected to the lever I53V and the control lever I58. The ends 405 and 405 of the control levers I67 and I-58 abut against the projections 295' so that when one of these levers is swung about its pivot IE? or IE8, the set of testing levers I59 associated with it is swung as a whole about their pivotal axes into or out of engagement as the case may be with the pair of code discs associated with that set.

The lowermost testing levers I59V and I581 of the two sets A and B have projections 259 and 298 which control an escapement for the printing mechanism.

The levers I5'I (Fig. 13) by means of which the testing levers I58 are displaced are pivotally mounted in bearings 235 on the rear side of the frame I2I. The levers I51 are curved at their free ends and end in lugs 23? disposed in a circular path wiped over by the lug I55 of the distributor arm I52 (Figs. 1, 2 and 'l). The lugs 93? have sloping surfaces and when the lug I55 passes over them, the free ends of their levers I5? are depressed.

The distributor arm I52 is fixed to the drum I53 (Fig. 2) which is free to move axially relatively to the sleeve I29 but is constrained to retate with the latter by the pins I55. The arm I53 and the drum I53 are acted on by a compres sion spring I55 which abuts against the flange I59 of the sleeve I29. The drum I53 in the right hand position illustratedv in Figure. 2 reaches almost to the base of the drum MI.

The drum I4! is fixed on the supporting frame I45. 10 slowly rising and suddenly falling cams I49 (Fig. '7) are distributed over its circumference. During half a revolution of the sleeve I29, these cams, by coming into contact with the two rearwardly projecting lugs I5! (Fig. 2) on the distributor arm I52 determine five forward and backward movements of the latter. The two lugs I5I ride at the same time, over oppositely disposed cams I49, the latter being arranged symmetrically on the drum MI.

The cranked end I41 of the armature MS of the magnet I projects through an opening M5 formed'in the lower part of the drum I II (Figs. 2 and 7). It prevents the drum I53 from being moved by the spring I55, as, while the lugs I5I are sliding over the cams I49, it slips between the edge of the drum I53 and the base of the drum I4! and remains here when the lugs I5I have passed clear of the cams I49.

The lever I4! is yieldingly connected to the armature I48 by means of a spring I99 (Fig. 7). This armature is periodically brought up to the pole I65 by the action of the cam disc I59 on the member I 54 fixed to the armature. The magnet I59 therefore only has to exert a magnetic force to hold the armature I43 attracted to the pole when the part IE4 is free of the cams I53. This release of the part I54 by the cam I53 always takes place at about the middle third of each signal impulse, at which instant, the signal current has reached its peak value. If this release takes place when no current is flowing, the armature I48 is turned anticlockwise by the spring I81 and the lever I41 comes out of contact with the drum I53.

The cam disc I69 is fixed to the sleeve I39 which also moves with the distributor arm I52 and the drum I53. The arrangement is so devised that the distributor arm I52 and the drum I53 are engaged by a cam I48 before the part I64 is engaged by a cam I53 and are released by the cam I49 at the earliest, at the same instant as the armature projection I54 is released by the cam I63. In this way, the engagement of the armature lever I47 between the drum I53 and the stationary drum MI is ensured. In order to synchronize the signal impulses and the rotation of the cam disc I50, the five successive cams I63 are advantageously made of increasing length.

The distributor arm I52 and the drum I53 can only be moved axially by the spring I55 when the lugs I5I lie between two of the cams I49 on the drum .I4I. When the magnet I'is energized, such axial movement is prevented by the lever I41 of the armature I40. The lugs 231 on the levers I51 are also disposed in the intervals between the cams I49.

If, then, the drum I53 is prevented from moving by the armature lever I41, the lug I56 on the arm I 52 abuts against the lug 231 formed on a leverl51 so that the associated testing lever I58 is transferred into its other extreme position. On the other hand, when the lug I5I of the arm I52 is allowed by the armature lever I41 to engage in the space between two of the cams I49, the lug I56 is out of the plane of the lugs 231 on the control levers I51. The latter therefore remain in the extreme forward position.

The extreme forward position of the levers I51 and the testing levers I58 is determined by a cam 238 (Figs. 1 and 13) before these levers are set by the lug I56 of .the arm I52. This cam 238 is arranged on the disc I62 at a given angle a (Fig. 13) in advance of the lug I56 on the arm I 52. In this way, shortly before the lug I56 wipes over the lugs 231, the testing levers I58 are brought successively into the forward position by engagement of the cam 238 with the rear side of the lugs 231, in which position they can be acted upon by the following lug I 56.

The levers I61 and I68 (Figs. 9 and 10) which rest on the uppermost testing levers I581 and I581 are controlled by a cam groove I6I in the wheel I62 and a follower pin I66 (Fig. 9). They are pivoted simultaneously, one inwards the other outwards during the last 7th part of each half revolution of the wheel I62.

When, at the end of the half revolution, the lever I61 (Fig. 9) has been brought into action the member 405 abuts against the free end 205 of the uppermost testing lever I58I of the set A. The blow is transmitted through the tails 204 to the lever I58V so that all the levers of the set A are swung clockwise about their bearing pins I98. Their ends 203 are thus removed from the grooves in the code discs I93, I94. At the same time, the lever I68 is swung so that its member 405' is removed away from the projection 205' of the lowermost lever I581 of the set B. The spring 206' pulls on the lever I58V' and all the levers of the set B are swung counterclockwise. The ends 203 of these testing leversnow lie on a pair of code discs I95, I96 but do not immediately engage in the grooves therein. (It cannot be assumed that out of the many cases that can occur, that case will be present in which the whole of the five testing levers will be opposite corresponding grooves in the discs and, therefore, be able to engage immediately therein.) Moreover, the testing levers of the set B remain under the influence of the spring 206 until all the testing levers can engage simultaneously and stop the code discs.

The code discs I93--I96 are rigidly connected to the flange 209 (Fig. 2) on the shaft I22. The

pair of code discs I93, I94 belonging to the set A is identical with the pair of discs I95, I96 belonging to the set B, but the two pairs are displaced through 180 relatively to each other. The discs in each pair are also similar except that one is provided withcams in the form of humps and the other with cams in the form of grooves.

The smallest cam in the code discs extends over part of its circumference. The distance between the ends 203 of the testing levers I58 in each set has a corresponding value. The ends 203 of all'thetesting levers of both sets are exactly the same;

The flange 209 can, if desired, be provided with a tooth in which can engage a check pawl for preventing recoil of the code discs when they are stopped by the testing levers. Such a pawl could be brought into action by the movement of the control levers I61 and I68.

The toothed wheel II5 (Figs. 1 and 2) is freely mounted on the shaft I22. It is frictionally connected to it both through the clutch plate 2I0 (Figure 2) and through the outermost code disc I96. The pressure exerted on the clutch plate 2I0 can be varied by displacement of a ring 2I2 and a resilient, split, dished disc 2H. The position of the ring 212 can be adjusted by means of a nut 2I3 and any setting can be maintained by means of a lock-nut 2I4.

As already stated, the drum I26 carrying the type wheel I25 is fixed to the type Wheel shaft I22 by means of a key 220. The type wheel carries groups of cam discs I21 or a grooved drum for controlling auxiliary devices.

The selecting mechanism operates as follows:

The code signal received in connection with the letter A consists firstly of a no current impulse (start element), then two current impulses, then three no current impulses and finally a 7th current impulse (stop element).

On reception of the start impulse, the sleeve I29 is coupled to the shaft II8 for half a revolution. During this rotation the distributor arm I52 is displaced axially five times against the action of the spring I by means of the lugs I5I which slide over the cams I49, once at the beginning of each of the five received current impulses. At the same time, a cam I63 on the disc I69 acts on the part I64 of the armature and brings the armature I48 up to the pole I65. At about the first third of each current impulse, (with disc I also of the stop impulse) the lugs I5I and IE4 reach the highest point of the cams.

The arm I52 is pressed back together with the drum I53 by the spring I55 as soon as the end of a cam I49 is reached. If the cranked end of the lever I41 is at this instant lifted and the armature attracted, the drum I53 cannot move backwards and the arm I52 remains in the displaced position in which its lug I56 acts on the lug 231 of the appropriate testing lever.

In the case under consideration, after the start impulse, the armature which has been brought near the pole remains attracted for two current impulses and thus prevents the return movement of the arm I52. The lug I56 on the distributor arm thus acts on the lugs 231 of the control levers I51I and I51II (Fig. 13), and thus displaces the testing levers I581 and II. The following three no-current impulses allow the armature which, on further movement towards the pole by means of the cam I63, meets no magnet holding force, to release and, as the lever I41 is also released, the arm I 52 and the drum I 53 to assume the right hand position illustrated in Figure 2. The three levers I51III, IV and V are thus not effected by the lug I56 and with the testing levers I58III, IV and V, remain unset.

The resetting cam 238 is in advance of the lug I56 of the distributor arm I52 and brings into the forward position the control lever I51 of the set A which is to be acted upon.

After reception of the signal, the testing levers I58IV of the set A are displaced as is shown in Figure 8 for the set B.

However, during the reception of the stop current impulse, the displaced levers of the set A are released by the lever I61 through the agency of the cam track I 6| in the wheel I62. The test ing levers are thus pivoted by the spring 2% acting on the end 205 of the lever I58V so thatthe ends 203 of these levers lie on the code discs I93 and I94 of the set A. The testing levers of the set E which up to now have been in engagement with their code discs are swung out of engagement as a set by the lever I68 which is caused to strike the tail 225 of the lever I531 (Fig. 10). The levers I58IV, however, are still not re turned into the forward normal position.

In the meantime, on reception of the stop impulse the maintenance of the sleeve I29 is prepared by the arm I52 and can be effected without influencing the succeeding steps.

As soon as the ends 203 of the testing levers in set B are removed from their operative position in the grooves of the discs I95 and IE6, all restraint is removed from the code discs and these are driven by the wheel H5 through the clutch 2M, H5. The 'shaft I22 and all the code discs and all the other parts rotate together at a relatively high speed.

The time required for a complete revolution of the shaft I22 corresponds approximately to the duration of five signal impulses on the assumption that two sets of testing levers are used.

During the rotation, all the ends 203 of the engaged set A of testing levers will slide on the code discs I93 and I94. These testing levers can engage in the grooves in these discs when, as illustrated in Figure 12 for the set B, the one appropriate position out of the 32 possible engaging positions is reached. In any other position, there may be from one to four of the levers I58 above corresponding grooves, but no engagement there in is possible because the abutment of the testing levers one on another only allows the levers to move all together, that is to say, as a set.

The engagement of the levers of the set A is accelerated by theaction of the spring 286. When the selecting position is reached, the shaft is suddenly stopped by the ends 203 of the testing levers I58IV. The impact caused on stoppage of the type wheel shaft I22 is received directly by the bearing pins I88 of the testing levers.

The relative positions assumed by the code discs and testing levers for the selection of the letter A (the case under consideration) is illustrated in Figure 12. Here, however, the selec tion was effected by the lever of the set 13 and the discs I95 and I96 of the set B which are displaced by 180 relatively to the code discs of the set A. The letter A on the type wheel I 25 is then in the printing position. The two sets A and B are used alternately for successive incoming signals. During one half revolution of the distributor arm I52, the testing levers of the set A are set and are released for cooperation with the discs I955, I92 and during the next half revolution, the levers of the set B are set and released for cooperation with the discs I95, I96.

The impulses transmitted to the magnet I59 from the transmitter are more or less distorted according to the conditions in the line.

It is usual, for the purpose of controlling the selecting mechanism, to use only those parts of the various impulses of the signal in which the most favourable current values occur. As the point at which the most favourable operating conditions occur varies, (although constant as regards the impulses of any one signal) the receiver has to be provided with a device for regulating the phase position of the selecting mechanism relatively to the start-stop mechanism.

At the first release of the armature M8 after the start impulse, the start-stop mechanism couples the shaft M8 to the sleeve I28 through the clutch wheels H5 and I32 for half a revolution. This sleeve I28 (Fig. 14) is coupled to the sleeve I29 of the selector gear by the dogs I35 on the flange I 36 which engage in the oblique grooves I34 at the forward end of the sleeve I28. The flange I36 is fixed to the sliding sleeve IZi'I which is guided the longitudinal slot I33 in the sleeve I29. The sliding sleeve I3! is formed with a circumferential groove in which half rings 29] are housed. The ring 391 is held by means of the nut I29 on the tubular screw threaded extension I40 of the fixed drum MI. The nut I39 has a milled head I42 with which engages resiliently a blade M3 mounted on the frame I l-5 (Fig. 2).

The ring I35 is displaced by rotation of the nut I39 which can be effected when the blade M3 is lifted. This rotation brings the dogs I35 against the walls of the oblique slot I34 which have a definite position in the normal position of the start-stop mechanism and the grooves I38 in the sleeve I 29 are caused to take up a new position relatively to the start-stop mechanism. The distributor arm I52 and the cam disc I68 are thus rotated relatively to the sleeve I28 of the start-stop mechanism.

The setting nut I35 can be provided with markings to determine the phase position of the selecting mechanism relative to the start-stop mechanism.

The arm I52 and its lugs I5! and E55 slide over the rising parts of the cams I49 on the fixed drum I l! and come up against the lugs 23! of the levers I5! controlling the testing levers I58 at particular instants of time during the received signal impulses, according to the relative phase positions assumed by the selecting mechanism and the start-stop mechanism. Also, by means of the cams I63 on the disc I62 (Fig. '7) the armature its is pressed towards the pole I25 at the appropriate most favourable instant of time.

In this way, the armature, the position of which determines the position of the drum I53 and the arm I52, is controlled with certainty by the magnet even with strongly distorted impulses. The most favourable phase position, which may vary quickly particularly with open line telegraph operation can be set and corrected during operation.

A printing device translates the position given to the type wheel shaft I22 by the selecting mechanism. If the shaft is in a position associated with letters or signals, printing will be effected; if in a position associated with switching steps, printing will be prevented.

This printing mechanism is controlled by the cam discs II--V on the carrier 2% (Fig. 15) which is mounted on the shaft IEB'I. The lever devices cooperating with these cams control further levers (not illustrated) some of which cooperate with the cam discs I2'l on the type drum IZE and others of which effect the release and return of the printing hammer 221.

The sleeve 2M by means of which the part 2262, (Figs. 15 and 16) of the clutch 255, 262 is fixed on the shaft IIl'I carries the sliding half 269 of the clutch. The part 260 is pressed towards the part 262 by a helical spring 255 which abuts against the carrer 264. The carrer 264 is freely mounted on the end of the shaft I01 and rotates with the part 269.

The cam discs IIV can be carried round through one-third of a revolution of the shaft 191 by means of the clutch 269, 262.

The clutch 269, 262 is controlled by a pawl 2M pivoted at 255. This pawl has two claws and 258 (Fig. 16) which cooperate with the diamond shaped projections 259 on the part 260 of the clutch. A spring 242, (Fig. 18) tends to keep the pawl 241 out of engagement with the projections 259.

The pawl MI is pivoted by a rod 249 hinged to it and pressed by the spring 242 against the front of two arms 249 and 250 pivotally mounted on a common pin 248 which is arranged in line with the rod' 240.

The arms 249 and 259 are pressed together by a spring 25I and can be swung about their hinge 248 by means of .a pin 252 on a T-shaped member 254 also pivotally mounted on the pin 248. The branches of the T-shaped member are engaged by control levers 24B and 221. The control levers 246 and 24'! can be acted on by the arms 298 and 208' (Figs. 9, 10 and 13) which are adjustably fixed to the testing levers i58V and I581.

The arrangement controlled by the rods 246 and 24! operates as follows:

When the testing levers of the set B (Figs. 9, 10 and 18) are removed from the code discs and the lever I581 is pivoted clockwise, the arm 208 moves away from the left hand end of the rod 24? (Figs. 15, 1'7 and 18). At the same time, the testing lever I58V of the set A is placed on its code disc and remains there until the ends 293 of the testing levers of this set A find it possible to engage in the discs in the so called testing position. As long as the lever I58V is not fully engaged, the arm 298 has no effective influence on the right hand end of the rod 245. When, however, the testing position is reached, (Fig. 18) the rod 246 is pressed towards the right by the arm 298 acting under the influence of the pull of the spring 206 which also accelerates the engagement in the code discs of the set of testing levers A. The T-shaped lever 248 carrying the pin 252 is thereby pivoted clockwise as is therefore the lever 249 against the front face of which the rod 249 has, up till now, been pressed. The lever 250 is also caused to turn by the spring 25!.

The rod 299 moves towards the right under the pull of the spring 242 and arrives in a position between the levers 249 and 250 and thus prevents the full pivotal movement of the arm 250 which remains in an intermediate position, (Figure 17) and causes the spring 25l to be extended.

It is only when, later on, the rod 249 is temporarily pressed towards the left that the arm 250 will move from its intermediate position under the influence of the tensioned spring 252 and abut against the arm 249 which has been swung into its extreme position (Fig. 19). The rod 240 now abuts against the front of the pivoted arm 259. It is only when the set of testing levers A has been made inoperative and the levers of the set B are placed on the code discs and have engaged therein and the pivoted levers 249, 250 are swung counter-clockwise, that the rod 249 and with it the pawl 24l are released.

There are three diamond shaped projections 259 spaced at equal intervals on the circumference of the clutch member 260 (Fig. 16). By means of these projections, the cam discs II-V are released for the duration of one-third of a revolution of the shaft I09. The cam discs IIV have threecorresponding humps'uniformly distributed over their circumference.

The clutch member 269 is permanently under the pressure of the helical spring 266 so that when released by the pawl 24!, it is moved to-' wards the wheel 262 for the purpose of clutching the cam discs II-V to the shaft I01.

When the pawl 24! is disengaged, the clutch member 269 is free for axial and angular movement (Fig. 1 Shortly before the end of of a revolution, the sloping face of the next projection 259 abuts against a correspondingsloping face on the arm 25'! of the pawl 24! which has been again brought into action in the meantime. Consequently, the clutch member 260 is displaced against the action of the spring 266 nd, as the projection 259 abuts against the head of the arm 258 of the pawl 24l is held after ex actly of a revolution. The cam disc II, chortly after the'b-eginning of the rotation of the carrier 26 i presses on the finger 268 of thepawl MI and, on further rotation, swings it against the action of the spring 262 into'the locking position. In this way, the rod 240 is again attracted to the left and then abuts on the front face of one of the levers 2&9 and 250 of the escapement mechanism. The pawl 2M is thus again held in its locked position.

During the rotation of the cam discs IIV for one-third of a revolution, various levers are actuated by these cam discs so as to influence the printing hammer for striking the type to which the type wheel has been set or to prevent printing and effect desired switching operations. The cams of the cam discs IIV also serve for the displacement of the paper to be printed and of the ink ribbon. This is not illustrated in detail as it is of no importance as regards the invention.

We claim:-

1. Type printing apparatus comprising a selecting device for determining a type according to received code current impulses of the Baudot type, said selecting device comprising a type wheel, a set of selecting discs connected to said type wheel, means for rotating said selecting discs and said type wheel, a set of testing members adapted to control said selecting discs, a setting device for setting said testing members relatively to said selecting discs, means for rotating said setting device, means for setting said setting device during its rotation, a magnet adapted tobe influenced by said code current impulses and provided with an armature adapted to influence the setting of said setting device, and means acted upon by said setting device during its rotation whereby to set said testing members successively under the influence of said means for rotating said setting device and in dependence upon said armature.

2. Apparatus as claimed in claim 1 in which said means for setting said setting device dur* ing its rotation comprise a stationary disc provided with cams on its-circumference adapted to displace said setting device axially during its rotation.

3. Apparatus as claimed in claim 1, in which said means for setting said setting device during its rotation comprise a fixed disc provided with a ring of cams arranged in pairs diametrically opposite each other and adapted to act simultaneously on said setting device to displace it axially.

4. Type printing apparatus comprising a selecting device for determining a type in accordance with received code current impulses of the Baudot type, said selecting device comprising a type wheel, a set of selecting discs connected to said type wheel, means for rotating said selecting discs and said type wheel, a set of testing members adapted to control said. selecting discs, a rotary se 'ng device for setting said testing nembers relatively to said selecting discs, a magnet adapted to be influenced by said code cur rent impuises and having an armature adapted to influence said setting device, a cam disc clutched to said setting device, means acted upon successively by the cams of said cam disc by to displace said armature intermittently dur ing rotation of said disc towards the pole of said. magnet, a stationary cam disc, means acted upon successively by the cams of said stationary disc whereby to intermittently displace said setting device axially during its rotation, a spring acting on said setting device and opposing said axial displacement of said setting device; said setting device, the cams of said movable cam disc the cams of said stationary cam disc being so arranged that the cams of the stationary cam disc release said setting device for axial displacement under the action of said spring, at the earliest, at the same time as that at which the cams of sai movable cam disc re ease said armature of said magnet.

5. Type printing apparatus comprising a seecting device for determining a type in accordance with received code current impulses of the Baudot type, said selecting device comprising a type wheel, a shaft for said type Wheel, two selecting discs arranged one beside the other on shaft and connected to said type wheel, means for rotating said selecting discs and said type wheel, a set of testing members adapted to control said selecting discs and arranged for displacement parallel to the shaft of said selecting discs, a setting device for setting said testmembers relatively to said selecting discs, a shaft for said setting device, said setting device being arranged for axial displacement on its shaft, means for rotating said setting device, stationary means for periodical axial displacement of said setting device during its rotation, a spring acting on said setting device in opposition to said means for axially displacing it, a magnet adapted to be influenced by said code c1v nt impulses and provided with anarmature adapted to hold said setting device in its axially displaced position against the action of said spring, means acted upon by said setting device in its axially displaced position whereby to set said testing members successively out of their normal position under the influence of said means provided for its rotation, a rotary resetting device for said testing members set in rotation by said means for rotating said setting device and disposed in advance of said setting device in the direction of rotation of the latter, means acted upon by said resetting device during its rotation whereby to return said testing members successively into their normal position. I

6. Type printing apparatus comprising a selecting device for determining a type in accordance with received code current impulses of the Baudot type, said selecting device comprisa type wheel, a shaft for said type wheel, two selecting discs arranged one behind the. other on said shaft and connected to said type wheel, means for rotating said selecting discs and said type wheel, a shaft parallel to the shaft of the selecting discs, a set of testing members on said last mentioned shaft adapted to control said selecting discs and arranged for axial and rotary displacement on said shaft, projections on said testing members whereby each of them is supported by the testing member below it in each of its axial positions, a setting device for axially displacing said testing members, means for rotating said testing members about their axes, a magnet adapted to be influenced by said code current impulses and having a projection adapted to influence said setting device.

7. Apparatus as claimed in claim 6, in which said selecting discs are provided on their circumference with grooves and humps and said testing members are provided with noses adapted on rotation of said testing members to be brought to lie on the circumference of said selecting discs and, on rotation of said discs to engage in said grooves in said selecting discs whereby to stop directly rotation of said selecting discs.

8. Apparatus as claimed in claim 6, comprising also a spring acting on said testing members and tending to rotate them as a whole about their axes, said means for rotating said testing members being constructed as a rotary disc comprising a controlling cam and a lever con trolled by said controlling cam. acting on said testing members for holding said testing members against rotation by said spring and for allowing such rotation.

'9. Type printing apparatus comprising a selecting device for determining a type in accordance with received code current impulses of the Baudot type, said selecting device comprising a selecting wheel, two sets of type discs connected to said selecting wheel, each of said two sets of type discs being of similar construction and being displaced relatively to each other through 180, means for rotating said sets of selecting discs and said type wheel, two sets of testing members, one set of selecting discs being associated with each of said sets of testing members, means controlled by each of said sets of testing members for controlling the associated set of selecting members, the testing members of each set having axes of rotation parallel to the axis of rotation of said selecting discs, the testing members of each set being provided with projections for mutual support of the testing members. of a set, a spring for each set of test ing members striving to rotate all the testing members of one set as a whole about their axes, said testing members being provided with noses adapted, on said testing members being rotated about their axes, to be brought to lie on. the circumference of said selecting discs, a control lever for each of said sets of testing members for preventing and for allowing movement of each set of testing members under the influence of said spring, a rotary disc provided with control cam for controlling said levers in such a Way that at any time there is only one set of testing members which is rotated under the influence of its spring, a rotary setting device, a magnet adapted to be influenced by said code current impulses, said magnet being provided with an armature adapted to influence said set ting device, and means acted upon by said setting device during its rotation whereby to displace the testing members of said two sets axially relatively to said selecting discs.

10. Type printing apparatus for printing type characters comprising a selecting device for determining a type in accordance with received code current impulses of the Baudot type, said selecting device comprising a type wheel, a set of selecting discs connected to said type wheel, means rotating said selecting discs and said type wheel, a set of testing members adapted to V influence said selecting discs, said testing members being displaceable relatively to said selecting discs, a rotary setting device for said testing members, a magnet adapted to be influenced by said code current impulses, said magnet being provided with an armature adapted to influence said setting device, means for rotating said setting device through one revolution, said last mentioned means being controlled by the arnia ture of said magnet and means for rotating said setting device relatively to said means for rotating it through one revolution.

r1. Type printing apparatus comprising a set of code discs, a typewheel, means for rotating said code discs and said type wheel in-unison, a magnet adapted to receive a train of current impulses of the Baudot type, a set of testing mem bers mounted for independent displacement,

means for arresting said code discs and said type wheel in various positions dependent upon the relative setting of said testing members, a source of power other than said magnet and means under the influence of said source of power for efiecting said relative setting of said testing members in accordance with the current impulses received by said magnet. 7

12. Type printing apparatus comprising a selecting device for determining a type-in accordance with received code current impulses of the Baudot type, said selecting device comprising a type wheel, a set of selecting discs connected to said type wheel, a set of testing members adapted to conrtol said selecting discs, a rotary member mounted for axial displacement during its rotation, means for rotating said rotary member, stationary means for displacing said rotary member axially during its rotation in one direction as said member passes through particular angular positions, a spring urging said rotary member axially in the other direction in all angular positions of said member, a magnet operated by said code current impulses and having an armature adapted to hold said rotary member against displacement by said spring, and means acted upon by said rotary member during its rotation whereby to set said testing member selectively in accordance with the axial displacements of said rotary member.

13. Type printing apparatus comprising a selecting device for determining a type in accordance with received code current impulses of the Baudot type, said selecting device comprising a type wheel, a set of selecting discs connected to said type wheel, means for rotating said selecting discs and said type wheel, a set of testing members adapted to control said type discs, a setting device for setting said testing members relatively to said selecting discs comprising a rotary arm, a ring adapted to rotate with said arm, means for rotating said arm, a stationary disc provided with camsadapted to displace said arm axially during its rotation, a spring constantly urging said arm towards said stationary disc, a stop adapted to engage between said ring and said disc whereby to hold said arm against displacement by said spring, electromagnetically controlled means adapted, under the influence of said code current impulses, to determine the en gagement of said step between said ring and said stationary disc and means acted upon by said arm during its rotation whereby to set said testing members selectively in accordance with the axial displacements of said arm.

14. Apparatus as claimed in claim 13, in which said electro-magnetic means comprise a magnet having an armature to which said stop is yieldingly connected.

15. Apparatus as claimed in claim 12, comprising also a cam disc adapted to move with said rotarymember, the cams of said cam disc being adapted to press said armature in a preparatory manner towards the pole of the magnet.

16. Apparatus as claimed in claim 12, comprising also a rotary cam disc adapted to be rotated together with said rotary member and having a, plurality of cams adapted to press said armature towards the pole of said magnet periodically during the reception of said code current impulses, said cams being arranged so as to act successively on said armature and being made of increasing lengths.

17. Apparatus for printing types selected in accordance with received current impulse signal trains of the Baudot type, comprising a type wheel, two sets of selecting discs, means for rotating said type wheel and said selecting discs in unison, two sets of testing members associated one with one and the other with the other of said sets of selecting discs, a magnet actuated by said received current impulse signal trains, means controlled by said magnet on receipt of successive trains for alternately setting the testing members of said sets of testing members into relative positions corresponding to the received train, means for bringing said sets of testing members individually with their testing members in said relatively displaced positions into contact with the associated selecting discs whereby to cause rotation of said discs to be arrested when said discs assume an angular position determining the selection of a type on said wheel corresponding to the received train, and a printing device comprising means .for producing an impression from said selected type, rotary means controlling said type impressing means, a clutch controlling the rotation of said rotary means and an escapement mechanism controlling said clutch, said escapement mechanism being controlled by said trains of testing members.

MAX AMANN. ALFRED LAHL. HANS HATZINGER. 

